installd.c revision 812b19a425b8304ac9e5408cc8ceb9f363c72559 
1/*
2** Copyright 2008, The Android Open Source Project
3**
4** Licensed under the Apache License, Version 2.0 (the "License");
5** you may not use this file except in compliance with the License.
6** You may obtain a copy of the License at
7**
8**     http://www.apache.org/licenses/LICENSE-2.0
9**
10** Unless required by applicable law or agreed to in writing, software
11** distributed under the License is distributed on an "AS IS" BASIS,
12** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13** See the License for the specific language governing permissions and
14** limitations under the License.
15*/
16
17#include <linux/capability.h>
18#include <linux/prctl.h>
19
20#include "installd.h"
21
22
23#define BUFFER_MAX    1024  /* input buffer for commands */
24#define TOKEN_MAX     8     /* max number of arguments in buffer */
25#define REPLY_MAX     256   /* largest reply allowed */
26
27static int do_ping(char **arg, char reply[REPLY_MAX])
28{
29    return 0;
30}
31
32static int do_install(char **arg, char reply[REPLY_MAX])
33{
34    return install(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
35}
36
37static int do_dexopt(char **arg, char reply[REPLY_MAX])
38{
39        /* apk_path, uid, is_public */
40    return dexopt(arg[0], atoi(arg[1]), atoi(arg[2]));
41}
42
43static int do_move_dex(char **arg, char reply[REPLY_MAX])
44{
45    return move_dex(arg[0], arg[1]); /* src, dst */
46}
47
48static int do_rm_dex(char **arg, char reply[REPLY_MAX])
49{
50    return rm_dex(arg[0]); /* pkgname */
51}
52
53static int do_remove(char **arg, char reply[REPLY_MAX])
54{
55    return uninstall(arg[0], atoi(arg[1])); /* pkgname, userid */
56}
57
58static int do_rename(char **arg, char reply[REPLY_MAX])
59{
60    return renamepkg(arg[0], arg[1]); /* oldpkgname, newpkgname */
61}
62
63static int do_fixuid(char **arg, char reply[REPLY_MAX])
64{
65    return fix_uid(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, gid */
66}
67
68static int do_free_cache(char **arg, char reply[REPLY_MAX]) /* TODO int:free_size */
69{
70    return free_cache((int64_t)atoll(arg[0])); /* free_size */
71}
72
73static int do_rm_cache(char **arg, char reply[REPLY_MAX])
74{
75    return delete_cache(arg[0]); /* pkgname */
76}
77
78static int do_protect(char **arg, char reply[REPLY_MAX])
79{
80    return protect(arg[0], atoi(arg[1])); /* pkgname, gid */
81}
82
83static int do_get_size(char **arg, char reply[REPLY_MAX])
84{
85    int64_t codesize = 0;
86    int64_t datasize = 0;
87    int64_t cachesize = 0;
88    int64_t asecsize = 0;
89    int res = 0;
90
91        /* pkgdir, persona, apkpath */
92    res = get_size(arg[0], atoi(arg[1]), arg[2], arg[3], arg[4],
93            &codesize, &datasize, &cachesize, &asecsize);
94
95    /*
96     * Each int64_t can take up 22 characters printed out. Make sure it
97     * doesn't go over REPLY_MAX in the future.
98     */
99    snprintf(reply, REPLY_MAX, "%" PRId64 " %" PRId64 " %" PRId64 " %" PRId64,
100            codesize, datasize, cachesize, asecsize);
101    return res;
102}
103
104static int do_rm_user_data(char **arg, char reply[REPLY_MAX])
105{
106    return delete_user_data(arg[0], atoi(arg[1])); /* pkgname, userid */
107}
108
109static int do_mk_user_data(char **arg, char reply[REPLY_MAX])
110{
111    return make_user_data(arg[0], atoi(arg[1]), atoi(arg[2])); /* pkgname, uid, userid */
112}
113
114static int do_rm_user(char **arg, char reply[REPLY_MAX])
115{
116    return delete_persona(atoi(arg[0])); /* userid */
117}
118
119static int do_clone_user_data(char **arg, char reply[REPLY_MAX])
120{
121    return clone_persona_data(atoi(arg[0]), atoi(arg[1]), atoi(arg[2]));
122}
123
124static int do_movefiles(char **arg, char reply[REPLY_MAX])
125{
126    return movefiles();
127}
128
129static int do_linklib(char **arg, char reply[REPLY_MAX])
130{
131    return linklib(arg[0], arg[1]);
132}
133
134static int do_unlinklib(char **arg, char reply[REPLY_MAX])
135{
136    return unlinklib(arg[0]);
137}
138
139struct cmdinfo {
140    const char *name;
141    unsigned numargs;
142    int (*func)(char **arg, char reply[REPLY_MAX]);
143};
144
145struct cmdinfo cmds[] = {
146    { "ping",                 0, do_ping },
147    { "install",              3, do_install },
148    { "dexopt",               3, do_dexopt },
149    { "movedex",              2, do_move_dex },
150    { "rmdex",                1, do_rm_dex },
151    { "remove",               2, do_remove },
152    { "rename",               2, do_rename },
153    { "fixuid",               3, do_fixuid },
154    { "freecache",            1, do_free_cache },
155    { "rmcache",              1, do_rm_cache },
156    { "protect",              2, do_protect },
157    { "getsize",              5, do_get_size },
158    { "rmuserdata",           2, do_rm_user_data },
159    { "movefiles",            0, do_movefiles },
160    { "linklib",              2, do_linklib },
161    { "unlinklib",            1, do_unlinklib },
162    { "mkuserdata",           3, do_mk_user_data },
163    { "rmuser",               1, do_rm_user },
164    { "cloneuserdata",        3, do_clone_user_data },
165};
166
167static int readx(int s, void *_buf, int count)
168{
169    char *buf = _buf;
170    int n = 0, r;
171    if (count < 0) return -1;
172    while (n < count) {
173        r = read(s, buf + n, count - n);
174        if (r < 0) {
175            if (errno == EINTR) continue;
176            ALOGE("read error: %s\n", strerror(errno));
177            return -1;
178        }
179        if (r == 0) {
180            ALOGE("eof\n");
181            return -1; /* EOF */
182        }
183        n += r;
184    }
185    return 0;
186}
187
188static int writex(int s, const void *_buf, int count)
189{
190    const char *buf = _buf;
191    int n = 0, r;
192    if (count < 0) return -1;
193    while (n < count) {
194        r = write(s, buf + n, count - n);
195        if (r < 0) {
196            if (errno == EINTR) continue;
197            ALOGE("write error: %s\n", strerror(errno));
198            return -1;
199        }
200        n += r;
201    }
202    return 0;
203}
204
205
206/* Tokenize the command buffer, locate a matching command,
207 * ensure that the required number of arguments are provided,
208 * call the function(), return the result.
209 */
210static int execute(int s, char cmd[BUFFER_MAX])
211{
212    char reply[REPLY_MAX];
213    char *arg[TOKEN_MAX+1];
214    unsigned i;
215    unsigned n = 0;
216    unsigned short count;
217    int ret = -1;
218
219//    ALOGI("execute('%s')\n", cmd);
220
221        /* default reply is "" */
222    reply[0] = 0;
223
224        /* n is number of args (not counting arg[0]) */
225    arg[0] = cmd;
226    while (*cmd) {
227        if (isspace(*cmd)) {
228            *cmd++ = 0;
229            n++;
230            arg[n] = cmd;
231            if (n == TOKEN_MAX) {
232                ALOGE("too many arguments\n");
233                goto done;
234            }
235        }
236        cmd++;
237    }
238
239    for (i = 0; i < sizeof(cmds) / sizeof(cmds[0]); i++) {
240        if (!strcmp(cmds[i].name,arg[0])) {
241            if (n != cmds[i].numargs) {
242                ALOGE("%s requires %d arguments (%d given)\n",
243                     cmds[i].name, cmds[i].numargs, n);
244            } else {
245                ret = cmds[i].func(arg + 1, reply);
246            }
247            goto done;
248        }
249    }
250    ALOGE("unsupported command '%s'\n", arg[0]);
251
252done:
253    if (reply[0]) {
254        n = snprintf(cmd, BUFFER_MAX, "%d %s", ret, reply);
255    } else {
256        n = snprintf(cmd, BUFFER_MAX, "%d", ret);
257    }
258    if (n > BUFFER_MAX) n = BUFFER_MAX;
259    count = n;
260
261//    ALOGI("reply: '%s'\n", cmd);
262    if (writex(s, &count, sizeof(count))) return -1;
263    if (writex(s, cmd, count)) return -1;
264    return 0;
265}
266
267/**
268 * Initialize all the global variables that are used elsewhere. Returns 0 upon
269 * success and -1 on error.
270 */
271void free_globals() {
272    size_t i;
273
274    for (i = 0; i < android_system_dirs.count; i++) {
275        if (android_system_dirs.dirs[i].path != NULL) {
276            free(android_system_dirs.dirs[i].path);
277        }
278    }
279
280    free(android_system_dirs.dirs);
281}
282
283int initialize_globals() {
284    // Get the android data directory.
285    if (get_path_from_env(&android_data_dir, "ANDROID_DATA") < 0) {
286        return -1;
287    }
288
289    // Get the android app directory.
290    if (copy_and_append(&android_app_dir, &android_data_dir, APP_SUBDIR) < 0) {
291        return -1;
292    }
293
294    // Get the android protected app directory.
295    if (copy_and_append(&android_app_private_dir, &android_data_dir, PRIVATE_APP_SUBDIR) < 0) {
296        return -1;
297    }
298
299    // Get the sd-card ASEC mount point.
300    if (get_path_from_env(&android_asec_dir, "ASEC_MOUNTPOINT") < 0) {
301        return -1;
302    }
303
304    // Get the android media directory.
305    if (copy_and_append(&android_media_dir, &android_data_dir, MEDIA_SUBDIR) < 0) {
306        return -1;
307    }
308
309    // Take note of the system and vendor directories.
310    android_system_dirs.count = 2;
311
312    android_system_dirs.dirs = calloc(android_system_dirs.count, sizeof(dir_rec_t));
313    if (android_system_dirs.dirs == NULL) {
314        ALOGE("Couldn't allocate array for dirs; aborting\n");
315        return -1;
316    }
317
318    // system
319    if (get_path_from_env(&android_system_dirs.dirs[0], "ANDROID_ROOT") < 0) {
320        free_globals();
321        return -1;
322    }
323
324    // append "app/" to dirs[0]
325    char *system_app_path = build_string2(android_system_dirs.dirs[0].path, APP_SUBDIR);
326    android_system_dirs.dirs[0].path = system_app_path;
327    android_system_dirs.dirs[0].len = strlen(system_app_path);
328
329    // vendor
330    // TODO replace this with an environment variable (doesn't exist yet)
331    android_system_dirs.dirs[1].path = "/vendor/app/";
332    android_system_dirs.dirs[1].len = strlen(android_system_dirs.dirs[1].path);
333
334    return 0;
335}
336
337int initialize_directories() {
338    int res = -1;
339
340    // Read current filesystem layout version to handle upgrade paths
341    char version_path[PATH_MAX];
342    snprintf(version_path, PATH_MAX, "%s.layout_version", android_data_dir.path);
343
344    int oldVersion;
345    if (fs_read_atomic_int(version_path, &oldVersion) == -1) {
346        oldVersion = 0;
347    }
348    int version = oldVersion;
349
350    // /data/user
351    char *user_data_dir = build_string2(android_data_dir.path, SECONDARY_USER_PREFIX);
352    // /data/data
353    char *legacy_data_dir = build_string2(android_data_dir.path, PRIMARY_USER_PREFIX);
354    // /data/user/0
355    char *primary_data_dir = build_string3(android_data_dir.path, SECONDARY_USER_PREFIX, "0");
356    if (!user_data_dir || !legacy_data_dir || !primary_data_dir) {
357        goto fail;
358    }
359
360    // Make the /data/user directory if necessary
361    if (access(user_data_dir, R_OK) < 0) {
362        if (mkdir(user_data_dir, 0711) < 0) {
363            goto fail;
364        }
365        if (chown(user_data_dir, AID_SYSTEM, AID_SYSTEM) < 0) {
366            goto fail;
367        }
368        if (chmod(user_data_dir, 0711) < 0) {
369            goto fail;
370        }
371    }
372    // Make the /data/user/0 symlink to /data/data if necessary
373    if (access(primary_data_dir, R_OK) < 0) {
374        if (symlink(legacy_data_dir, primary_data_dir)) {
375            goto fail;
376        }
377    }
378
379    if (version == 0) {
380        // Introducing multi-user, so migrate /data/media contents into /data/media/0
381        ALOGD("Upgrading /data/media for multi-user");
382
383        // Ensure /data/media
384        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
385            goto fail;
386        }
387
388        // /data/media.tmp
389        char media_tmp_dir[PATH_MAX];
390        snprintf(media_tmp_dir, PATH_MAX, "%smedia.tmp", android_data_dir.path);
391
392        // Only copy when upgrade not already in progress
393        if (access(media_tmp_dir, F_OK) == -1) {
394            if (rename(android_media_dir.path, media_tmp_dir) == -1) {
395                ALOGE("Failed to move legacy media path: %s", strerror(errno));
396                goto fail;
397            }
398        }
399
400        // Create /data/media again
401        if (fs_prepare_dir(android_media_dir.path, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
402            goto fail;
403        }
404
405        // /data/media/0
406        char owner_media_dir[PATH_MAX];
407        snprintf(owner_media_dir, PATH_MAX, "%s0", android_media_dir.path);
408
409        // Move any owner data into place
410        if (access(media_tmp_dir, F_OK) == 0) {
411            if (rename(media_tmp_dir, owner_media_dir) == -1) {
412                ALOGE("Failed to move owner media path: %s", strerror(errno));
413                goto fail;
414            }
415        }
416
417        // Ensure media directories for any existing users
418        DIR *dir;
419        struct dirent *dirent;
420        char user_media_dir[PATH_MAX];
421
422        dir = opendir(user_data_dir);
423        if (dir != NULL) {
424            while ((dirent = readdir(dir))) {
425                if (dirent->d_type == DT_DIR) {
426                    const char *name = dirent->d_name;
427
428                    // skip "." and ".."
429                    if (name[0] == '.') {
430                        if (name[1] == 0) continue;
431                        if ((name[1] == '.') && (name[2] == 0)) continue;
432                    }
433
434                    // /data/media/<user_id>
435                    snprintf(user_media_dir, PATH_MAX, "%s%s", android_media_dir.path, name);
436                    if (fs_prepare_dir(user_media_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
437                        goto fail;
438                    }
439                }
440            }
441            closedir(dir);
442        }
443
444        version = 1;
445    }
446
447    // /data/media/obb
448    char media_obb_dir[PATH_MAX];
449    snprintf(media_obb_dir, PATH_MAX, "%sobb", android_media_dir.path);
450
451    if (version == 1) {
452        // Introducing /data/media/obb for sharing OBB across users; migrate
453        // any existing OBB files from owner.
454        ALOGD("Upgrading to shared /data/media/obb");
455
456        // /data/media/0/Android/obb
457        char owner_obb_path[PATH_MAX];
458        snprintf(owner_obb_path, PATH_MAX, "%s0/Android/obb", android_media_dir.path);
459
460        // Only move if target doesn't already exist
461        if (access(media_obb_dir, F_OK) != 0 && access(owner_obb_path, F_OK) == 0) {
462            if (rename(owner_obb_path, media_obb_dir) == -1) {
463                ALOGE("Failed to move OBB from owner: %s", strerror(errno));
464                goto fail;
465            }
466        }
467
468        version = 2;
469    }
470
471    if (ensure_media_user_dirs(0) == -1) {
472        ALOGE("Failed to setup media for user 0");
473        goto fail;
474    }
475    if (fs_prepare_dir(media_obb_dir, 0770, AID_MEDIA_RW, AID_MEDIA_RW) == -1) {
476        goto fail;
477    }
478
479    // Persist layout version if changed
480    if (version != oldVersion) {
481        if (fs_write_atomic_int(version_path, version) == -1) {
482            ALOGE("Failed to save version to %s: %s", version_path, strerror(errno));
483            goto fail;
484        }
485    }
486
487    // Success!
488    res = 0;
489
490fail:
491    free(user_data_dir);
492    free(legacy_data_dir);
493    free(primary_data_dir);
494    return res;
495}
496
497static void drop_privileges() {
498    if (prctl(PR_SET_KEEPCAPS, 1) < 0) {
499        ALOGE("prctl(PR_SET_KEEPCAPS) failed: %s\n", strerror(errno));
500        exit(1);
501    }
502
503    if (setgid(AID_INSTALL) < 0) {
504        ALOGE("setgid() can't drop privileges; exiting.\n");
505        exit(1);
506    }
507
508    if (setuid(AID_INSTALL) < 0) {
509        ALOGE("setuid() can't drop privileges; exiting.\n");
510        exit(1);
511    }
512
513    struct __user_cap_header_struct capheader;
514    struct __user_cap_data_struct capdata[2];
515    memset(&capheader, 0, sizeof(capheader));
516    memset(&capdata, 0, sizeof(capdata));
517    capheader.version = _LINUX_CAPABILITY_VERSION_3;
518    capheader.pid = 0;
519
520    capdata[CAP_TO_INDEX(CAP_DAC_OVERRIDE)].permitted |= CAP_TO_MASK(CAP_DAC_OVERRIDE);
521    capdata[CAP_TO_INDEX(CAP_CHOWN)].permitted        |= CAP_TO_MASK(CAP_CHOWN);
522    capdata[CAP_TO_INDEX(CAP_SETUID)].permitted       |= CAP_TO_MASK(CAP_SETUID);
523    capdata[CAP_TO_INDEX(CAP_SETGID)].permitted       |= CAP_TO_MASK(CAP_SETGID);
524
525    capdata[0].effective = capdata[0].permitted;
526    capdata[1].effective = capdata[1].permitted;
527    capdata[0].inheritable = 0;
528    capdata[1].inheritable = 0;
529
530    if (capset(&capheader, &capdata[0]) < 0) {
531        ALOGE("capset failed: %s\n", strerror(errno));
532        exit(1);
533    }
534}
535
536int main(const int argc, const char *argv[]) {
537    char buf[BUFFER_MAX];
538    struct sockaddr addr;
539    socklen_t alen;
540    int lsocket, s, count;
541
542    ALOGI("installd firing up\n");
543
544    if (initialize_globals() < 0) {
545        ALOGE("Could not initialize globals; exiting.\n");
546        exit(1);
547    }
548
549    if (initialize_directories() < 0) {
550        ALOGE("Could not create directories; exiting.\n");
551        exit(1);
552    }
553
554    drop_privileges();
555
556    lsocket = android_get_control_socket(SOCKET_PATH);
557    if (lsocket < 0) {
558        ALOGE("Failed to get socket from environment: %s\n", strerror(errno));
559        exit(1);
560    }
561    if (listen(lsocket, 5)) {
562        ALOGE("Listen on socket failed: %s\n", strerror(errno));
563        exit(1);
564    }
565    fcntl(lsocket, F_SETFD, FD_CLOEXEC);
566
567    for (;;) {
568        alen = sizeof(addr);
569        s = accept(lsocket, &addr, &alen);
570        if (s < 0) {
571            ALOGE("Accept failed: %s\n", strerror(errno));
572            continue;
573        }
574        fcntl(s, F_SETFD, FD_CLOEXEC);
575
576        ALOGI("new connection\n");
577        for (;;) {
578            unsigned short count;
579            if (readx(s, &count, sizeof(count))) {
580                ALOGE("failed to read size\n");
581                break;
582            }
583            if ((count < 1) || (count >= BUFFER_MAX)) {
584                ALOGE("invalid size %d\n", count);
585                break;
586            }
587            if (readx(s, buf, count)) {
588                ALOGE("failed to read command\n");
589                break;
590            }
591            buf[count] = 0;
592            if (execute(s, buf)) break;
593        }
594        ALOGI("closing connection\n");
595        close(s);
596    }
597
598    return 0;
599}
600